Portable mop wringers and mop bucket assemblies are known generally in the prior art. The following patent documents are believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 7,437,795, issued Oct. 21, 2008, U.S. Pat. No. 8,696,028, issued Apr. 15, 2014, U.S. Pat. No. 8,635,736, issued Jan. 28, 2014, U.S. Pat. No. 4,928,505, issued May 29, 1990, U.S. Pat. No. 8,381,931, issued Feb. 26, 2013, U.S. Pat. No. 7,434,292, issued Oct. 14, 2008, U.S. Pat. No. 3,987,513, issued Oct. 26, 1976, U.S. Pat. No. 1,922,981, issued Aug. 15, 1933, U.S. Patent App. Pub. No. US 2003/0217428, published Nov. 27, 2003 and U.S. Patent App. Pub. No. US 2014/0263104, published Sep. 18, 2014.